Isolator on extractor fan

[EFLImpudence]

Mould only grows on surfaces that never dry.

What I do, do is read lots of complaints of mould on here, it the cause always seems to trace back to poor ventilation of bathrooms, rather than lack of warmth.

It's a mixture of both.

You forgot to mention: very humid rest of the property because of poor ventilation, washing drying indoors, cooking in unventilated kitchen, many indoor plants, fish tanks, several people, several big dogs etc.

 

[JohnW2]

As I keep repeating, we have no mould issue here.

I don't think anyone has suggested that you do. I don't have a mould issue, either. So what? We are talking about the effectiveness of measures taken by people who do have 'a mould issue'.

I don't visit many of other people's bathrooms, why would I?

Even if you visited many bathrooms, that wouldn't help. The only way of knowing how much success people have had in eliminating mould by installing an extractor fan is from historical reports/'stories'.

I really don't understand why you seem so intent on arguing. I merely made the point that the temperature of surfaces and amount of ventilation are both relevant to the reduction of condensation (hence potential mould growth), and that many people with a mould problem seem to have limited success by addressing it by just installing an extractor.

 

[Harry Bloomfield]

I can only look at this from my experience in the controls industry, in situations where warm moving water is likely the air temp is commonly set at a minimum of 2 degrees higher than the water temp.

In the water supply industry, I was familiar with, control cabinets, were simply fitted with heaters in the bottom of the cabinet. Either the usual tube heater, or the large, gold resistor type. Fans were simply not needed in the cabinets, until electronics came along, and big triacs for variable speed motors.

 

[Harry Bloomfield]

I really don't understand why you seem so intent on arguing.

Are you not doing exactly the same John, is it not one of your well known traits in any discussion?

 

[JohnW2]

You forgot to mention: very humid rest of the property because of poor ventilation, washing drying indoors, cooking in unventilated kitchen, many indoor plants, fish tanks, several people, several big dogs etc.

Indeed - but an interesting observation is that in houses which are 'reasonably heated', it's not very common to hear of mould problems other than in bathrooms.

 

[JohnW2]

Are you not doing exactly the same John, is it not one of your well known traits in any discussion?

I don't think so. I just posted one comment and that potentially could have been the end of it - it is your responses that has turned it into a protracted exchange.

 

[Harry Bloomfield]

Indeed - but an interesting observation is that in houses which are 'reasonably heated', it's not very common to hear of mould problems other than in bathrooms.

Back in the mid-80's we had central heating installed, but nothing effective done about ventilation. It was warm, but moist, we had mould. Simply adding proper ventilation, sorted the mould issues.

 

[JohnW2]

Exposed water which gives rise to wet air such as bathing areas.

In that case, I don't really understand what you wrote. If the 'warm moving water' you mentioned is, in fact, 'wet air', what did you mean by setting the 'air temperature' at 2 degrees higher than the 'wet air' temperature?

 

[EFLImpudence]

Indeed - but an interesting observation is that in houses which are 'reasonably heated',

Well, I suppose you will have to define 'reasonably heated' and is 'what' in houses which are 'reasonably heated' .

I will point out that I have never had a bathroom extractor fan in any of the UK properties I have lived in and never had any mould.
Also, condensation and associated mould does not occur in unoccupied (cold) properties.

it's not very common to hear of mould problems other than in bathrooms.

Not according to the recent news and ill-informed Government legislation

 

[Harry Bloomfield]

Indeed - but an interesting observation is that in houses which are 'reasonably heated', it's not very common to hear of mould problems other than in bathrooms.

You maybe need to read some of the posts in the General forum, where there are lots of questions about mould, other than in bathrooms.

 

[EFLImpudence]

I don't think so. I just posted one comment and that potentially could have been the end of it - it is your responses that has turned it into a protracted exchange.

That's a bit of a cheek.

 

[Harry Bloomfield]

It's a mixture of both.

You forgot to mention: very humid rest of the property because of poor ventilation, washing drying indoors, cooking in unventilated kitchen, many indoor plants, fish tanks, several people, several big dogs etc.

If the air, is warmer than the walls, and the air is humid enough, it will condense out on the walls, and trigger mould. Even in winter, if the doors and windows are opened wide, with no heating, there will be no mould formed, providing the roof is sound.

Warm interior, with cold walls, plus habitation, and inadequate ventilation, you get mould forming.

 

[JohnW2]

Back in the mid-80's we had central heating installed, but nothing effective done about ventilation. It was warm, but moist, we had mould. Simply adding proper ventilation, sorted the mould issues.

Fair enough. If the problem involves the whole house, there are obviously potential energy/cost issues involved with continuously extracting the heated air from the whole house (unless one has some fancy heat-recovery system!).

It would seem sensible to start by eliminating/reducing major avoidable sources of humidity (such as drying of washing), including specific extraction of above-cooker air etc., and maybe even to consider the use of dehumidifiers.

Ironically, in the days when many were installing central heating for the first time, one of the 'complaints' was about 'dry air', which lead in some cases to deliberate measures to 'humidify' the air!

 

[JohnW2]

That's a bit of a cheek.

I don't see why. If Harry hadn't disagreed with my initial comment, I see no reason why I would have written anything more about it.

 

[EFLImpudence]

If the air, is warmer than the walls, and the air is humid enough, it will condense out on the walls, and trigger mould. Even in winter, if the doors and windows are opened wide, with no heating, there will be no mould formed, providing the roof is sound.

Warm interior, with cold walls, plus habitation, and inadequate ventilation, you get mould forming.

Mould only grows on surfaces that never dry.


It's a mixture of both.

You forgot to mention: very humid rest of the property because of poor ventilation, washing drying indoors, cooking in unventilated kitchen, many indoor plants, fish tanks, several people, several big dogs etc.

I will point out that I have never had a bathroom extractor fan in any of the UK properties I have lived in and never had any mould.
Also, condensation and associated mould does not occur in unoccupied (cold) properties.